Short answers, pulled from the story.
Union cavalry forces under Maj. Gen. Philip Sheridan defeated Confederate troops led by Maj. Gen. J.E.B. Stuart at an abandoned inn north of Richmond. The Union army outnumbered the Confederates and utilized superior firepower from Spencer carbines to hold the field for over three hours.
A dismounted Union private named John A. Huff mortally wounded Maj. Gen. J.E.B. Stuart with a .44-caliber revolver shot. This event occurred around noon on the 11th of May 1864 when Stuart was shouting encouragement to his men near a low ridgeline.
Robert E. Lee lost Maj. Gen. J.E.B. Stuart after he died in Richmond on the 12th of May 1864 following a mortal wound received at Yellow Tavern. Stuart had commanded the Confederate cavalry until his death which left Lee without direct cavalry coverage for two weeks.
The Union cavalrymen suffered 625 casualties during the engagement while capturing 300 Confederate prisoners. They also recovered almost 400 Union soldiers who had been captured earlier in the Battle of the Wilderness.
Philip Sheridan aimed to defeat Jeb Stuart, disrupt Lee's supply lines by destroying railroad tracks and supplies, and threaten the Confederate capital in Richmond. His force included over 10,000 troopers with 32 artillery pieces that moved behind Lee's army starting on the 9th of May 1864.